Hydraulic bean cleaning process and apparatus

Abstract

A hydraulic bean cleaner for removing rocks from beans has a hopper for gravity-feeding uncleaned beans down an inner cylindrical tube into a cylindrical separator tank. The inner tube has a bean discharge opening centered just above the bottom of the tank. An outer cylindrical tube concentrically surrounds the inner tube, providing an annular passageway therebetween and a water discharge opening surrounding the bean discharge opening. A first vibrator vibrates the tubes as a unit to help feed the beans down the inner tube. A second vibrator vibrates the hopper independently of the tubes to aid in feeding the beans to the inner tube. The beans drop into the bottom of the tank and water is expelled downwardly into the tank around them. The water entrains and fluidizes the beans, carrying them laterally away from the bean discharge opening and buoying them upwardly. The turbulent flow of water agitates the beans. Agitation of the fluidized beans creates spaces between the beans through which rocks can sift downward to the bottom of the tank against the upward flow of the water. Near the top of the tank the beans and water overflow across a spillway into a colander. The colander strains the water into a sump. A pump recirculates the water in the sump back to the outer tube.